Electric resistor device



Dec. 12, 1961 c. R. JOSLYN 3,013,239

ELECTRIC RESISTOR DEVICE Filed Dec. 18, 1958 2 Sheets-Sheet 1 Ff Q. J |7 l6 2| INVENTOR.

CARL ROBERT JOSLYN www ATT NEYS Dec. 12, 1961 c. R. JOSLYN 3,013,239

ELECTRIC RESISTOR DEVICE Filed Dec. 18, 1958 2 Sheet -Sheet 2 fq j 22 IN V EN TOR.

-5 ARL ROBERT JOSLYN q 2y QEMM/MZQ ATTORN S 7 3,913,239 Patented Dec. 12, 1961 United States Patent fli 3,013,239 ELECTRIC RESISTOR DEVICE CarlRobert Joslyn, Sidney, N.Y., assignor to The Bendix Corporation, a corporation of Delaware Filed'Dee. l8, 1958, Ser. No. 781,291

17 Claims. (Cl. 338-617) This invention relates to an electrical circuit device, and more particularly relates to a separable electrical connector having a circuit modifying element incorporated as a permanent part thereof. In the illustrative embodiment, the electrical circuit device is shown as one of a plurality of separable connectors incorporated in a ladder-type thermocouple harness, each such connector incorporating compensating-resistors.

The invention has among its objects the provision of a novel electrical circuit device having a divided electrically insulating housing and novel. means for retaining the housing p arts in assembled relation and for making elec trical contact with the circuit element.

A further object of the, invention lies in the provision of a novel separableelectrical connector, said connector incorporating a circuit modifyingelectrical element as a part thereof. g

Yet another object of the invention lies in the provision of a novel hermeticallycerled electrical connector having a housing, said circuit-modifying element being sealed within the housing.

Still a further object of i the invention resides in the provision of an improved separable electrical connector adapted forincorporation in a multiple thermocouple circuit of the ladder-type, said connector incorporating compensating'resistors. I

The above and further objects and novel features of the present invention will more fully appear from the followingdetailed description when'the same is read in connection with the accompanyingdrawings. it is to be expressly understood, however, that the drawings are for the purpose of illustration only and are not intended as a definition of the limits of the invention, reference for this latter purpose being had primarily to the appended claims. I

In'the drawings; whereinlikereference characters refer to like parts throughout'the several views, v

FIG. 1 isarwiring diagram of a multiple 'thermocouple harness of the ladde'r type;

FIG Z isa'fragmehtary view in vertical axial section througha' separable electrical' connector for one ofthe intermediatethermocouples in'the'circuit of FIG. 1, certainof the parts bein'gshoivn in elevation;

FIG; 3- is a' fragmentary view on a smaller scale in horizontal section" through the connector and cable portions shown inFIGL 2, the section beingtaken. generally along'the line 33 of FIG. 2;

FIG; 4 is a fragmentary view partially in axial section and partially in elevation of the terminal or output connectorfo'r the thermocouple harness; 7

FIG. 5 is a View in' vertical axial section similar to FIG. 2, but on 'anenlar'ged scalejcertain of the parts shown in FIG. 2, particularly the lid or'cover'and thc ends of the cables connected tothe housing of the connector, being omitted;

FIG. 6 is a view in plan of the connector as it is shown in FIG. 5, the view being taken from the point of view of 6-5 of FIG. 5;

FIG. 7 is a view in horizontal section through the connector'ofFlGS. 2 and 5 at the location of the compensating resistors; the section being taken along the line 7-7 of FIG. 5; and V FIG. 8 is an enlarged fragmentary view in vertical section' through tlreh'ousing of thecompensating resistor element of the connector, the section being taken generally along the line of FIG. 7, certain parts being omitted forclarity of illustration.

The apparatus ofthe invention is illustrated herein in its application to a multiple thermocouple harness of the so-called ladder-type. Such harness includes'a plurality of thermocouples connected in parallel and delivering their combinedoutput to a single output circuit. The indicating and/ or recording device-connected to the output circuit therefor indicates the average of voltages generated by the several thermocouples. In order to make the device sufficiently accurate for most test purposes, it is necessary to provide compensation for the different lengths of the lead wires connected to the respective thermocouples, Where only moderate accuracy is required, it is conven tional to employ a compensatingresistor in only one side of the cable leading to each thermocouple. Where greater accuracy is demanded, it is conventional to employ a separate compensating resistor in each side of the line leading to each thermocouple.

The provision of one or two compensating resistors for each thermocouple presents no serious problems, whereas in the laboratory, space is not at a premium and a circuit and generallythe thermocouple circuit need not be sealed. Serious difiiculties are encountered however, when the thermocouple circuit mustbe sealed, when it is subjected to Wide variations in temperature and in atmospheric pressure, and when weight and space are at a premium. A typicaluse for a multiple thermocouple circuit of the ladder-type made in accordance with the invention is for the detection of the temperature of the combustion chamber of a large jet engine. In such application a plurality of thermocouples, which mayrange in number from 8 to 36, for example, are mounted so as to be distributed over the extentof the combustion chamber. In such use, the thermocouple system encounters temperatures ranging from 72 F. to as high as 1500 F. and is subjected to atmospheric pressures varying from that of ground level to that of 50 to 60 thousand feet.

The ladder-type thermocouple circuit and the separable electrical connectors therefor are of such construction that they successfully meet the arduous requirements for use on a jet engine. The circuit-forming elements including the connectors, are simple andcompact, and may be readily hermetically sealed. The incorporation of the compensating resistor element in the connector adds but little to its volume and weight. The resistor-containing.assembly is of such construction and is so mounted within the connector housing as to be separable therefrom. The resistor-car rying element is of such construction that it may be opened, if necessary, to replace one or more of the resistors of the compensating resistors therein.

Turning now to the drawings, there is shown in FIG. 1 a ladder-type thermocouple harness, generally designated 10, having'eight thermocouples connected in parallel to asingle output circuit. The mainleadsof such harness are designated 11 and 12, there being two terminal thermocouple connector's'14 connected to such leads, and six intermediate the'mocouple connectors 15 connected thereto. The thermocouple connectors 14 and 15 are similar with the exception that one cable is connected to the terminal thermocouple connectors whereas two cables areconnected to the. intermediate thermocouple connectors. Preferably thermocouple connectors 14 and 15 are distributed along lead wires 11am 12 at each side of the location of connection of the output circuit composed of lead wires 16 and 17. Aseparable electrical connector 19, shown in 'mor'e detail in FIG. 4, is connected to the ends of wires 16 and 17, which are parts of a cable having an impervious sheath 21 sealed tofthe housing of connector 19.

In FIGS. 2 to 8, inclusive, there is shown the construction or" a connector for one of the intermediate thermocouples of the circuit 1t connector 35 being made in accordance with the invention. Connector 15 has a metal housing which has at its upper end, generally designated 22, two aligned and oppositely directed sleeves 24 integral therewith for the reception of the impervious sheaths of the cable sections containing lead wires 11 and 12 of the harness. The upper end of the housing has a wide opening therethrough, the opening being sealed after assembly of the connector parts by a disk or lid 25 which is sealed to the housing as by being edge-welded thereto. Below laterally directed sleeves 24, the housing has a vertically directed cylindrical portion 26 which is welded to a lower housing sleeve having an upper cylindrical portion 29 aligned with housing portion 26. Mounted within housing portion 29 is a transversely disposed electrically insulating ceramic member 39 which is yieldably mounted upon and sealed to the housing, and which mounts two socket contacts 34 and 35. Ceramic member 30 has its periphery metallized and brazed to the vertically extending sleeve portion of a flexible diaphragm 31. Diaphragm 31 has an annular inbent portion above member 30, the upper outer edge of the diaphragm being formed as a horizontal outwardly extending flange which is interposed between the confronting edges of housing portions '26 and 29. An annular weld designated at 32, sealingly connects portions 26 and 29 and the upper outer edge of diaphragm 31 together.

Ceramic member 30 has two relatively large vertical openings therethrough, each opening accommodating a cup-like flexible diaphragm 36. The upper side wall of each diaphragm 36 is sealed to member 30 by being brazed to the metallized wall of the respective opening in the member. A nut 37 disposed about the lower end of the housing of the connector, allows the connector part shown to be held in operative confronting relationship with a somewhat generally similarly constructed connector part having connector pins received within the respective socket contacts 34 and 35.

It is preferable with thermocouple circuits employed to measure temperatures with high accuracy to have the respective lead wires, including the connector parts inserted therein, of the same metals as the respective sides of the thermocouple. Accordingly, assuming that the thermocouples employed are of the Chromel-Alumel type, the connector pin, the socket contact 34, the compensating resistor, and the other parts connected in series with the Chromel side of the thermocouple will all be made of Chromel, and the similar parts of the Alumel side of the thermocouple circuit will all be rriade of Alumel. For simplicity of assembly, the various connector parts are distinctively marked as by being distinctively grooved.

The unit carrying the compensating resistors is generally designated 39. Such unit is mounted within the portion 26 of the housing of connector part 15. Resistor unit 39 houses two separate resistors, each connected in series with its respective socket contact. The resistor unit also includes upwardly projecting connector pins by means of which the resistors are connected in circuit in the harness. The manner of construction of unit 39 and of its assembly in the connector part will be more readily apparent upon consideration of FIGS. 5 to 8, inclusive.

Integrally connected with the upper end of socket contact 34 is an upstanding connector pin 40. Socket contact 34 has a generally similar pin 41 connected thereto. Unit 39, which is generally of disk-shaped, fits loosely within portion 26 of the housing, conveniently initially resting upon diaphragm 41 after assembly in the housing. Unit 39 incorporates connector sleeves, to be described, which telescopically receive pins and 41.

Element 39 has an electrically insulating housing which is split horizontally, the lower part 45 being of plate-like shape and the upper portion 46 being somewhat thicker and having two similar recesses 47 and 49 therein sepa- 4 rated by a central web 50. When the housing parts are held together, they define two essentially closed spaces each containing its respective compensating resistor 51 and 52. A first pair of diametrically opposed sleeves 54, 54 extend vertically through the housing of element 39 generally at one end of each of recesses 47 and 49. A second pair of diametrically opposed sleeves 55, 55 extend through openings through the upper and lower parts of the housing of element 39, each generally at the other end of the respective recesses 47 and 49. Sleeves 54 are so spaced apart as to receive pins 40 and 41 therein. Sleeves 55, which lie in a plane at right angles to that containing sleeves 54, receive pins 42 and 44 therein.

Compensating resistors 51 and 52 are each wound of wire made of the same metal as the side of the thermocouple circuit in which it is incorporated. The respective pins 40, 41, 42, and 44 and sleeves 54 and 55 are likewise made of Chroinel or Alumel, as the case may be. Each of sleeves 54 and 55 is initially made generally of circular cylindrical shape so that its ends may be telescoped through the openings in the respective housing parts 45 and 46 of element 39. Each of the sleeves has a peripherally extending flange 56 located generally centrally thereof and lying within the respective cavity 47 and 49. The flange 56 is peripherally grooved, and receives within it the respective end of the wire forming the resistor. The flange is crimped at the location of the wire and is then spot welded thereto.

Two assemblies of sleeves and resistors are made, and

are then mounted within the cavities 47 and 49 in the housing. The opposite ends of sleeves 54 and 55 are then flared as shown in FIG. 5 so as to hold the housing parts 45 and 46 tightly in contact. The pins 42 and 44 are now inserted within the sleeves 55 and are brazed thereto. The resistor unit 39 is now complete.

It will be assumed that the connector part 15 has been assembled to the stage shown in FIG. 5, but that the resistor unit 39 has not been mounted therein, the cables have not been connected thereto, nor has the connector housing been sealed by the welding of lid 25 thereto. The resistor unit is then introduced into the housing through the opening at the top thereof and is lowered so that pins 40 and 41 are telescoped within sleeves 55. The pins and sleeves are now brazed together, as by placing rings of brazing material in the wells provided between the upper ends of the pins and the flared ends of the sleeves, the assembly being then charged into a furnace to melt the brazing metal to secure the parts together. Following this, the cable portions are mounted within the laterally extending sleeves 24 of the housing and the ends of lead wires 11 and 12, which have previously been supplied with connecting lugs 62, are connected and brazed to the upper ends of pins 42 and 44. The lid 25 may now be applied to the upper end of the housing and edge-welded thereto.

Although only one embodiment of the invention has been illustrated in the accompanying drawings and described in the foregoing specification, it is to be expressly understood that various changes, such as in the relative dimensions of the parts, materials used, and the like, as well as the suggested manner of use of the ap paratus of the invention, may be made therein without departing from the spirit and scope of the invention as will now be apparent to those skilled in the art.

What is claimed is:

1. An electrical circuit device comprising an electrically insulating housing having two parts forming a cavity therebetween, a circuit element in said cavity, contact means connected to said element, said contact means also serving to retain the two parts of the housing in closed position, the contact means having a flange thereon within the cavity, the flange having a circumterentially extending slot therein, and the element having a lead wire extending generally tangentially of the flange and received in and electrically connected to the slot.

2. An electrical circuit device as claimed in claim 1, wherein the contact means is a generally cylindrical element extending normal to the container parts, and comprising means on the contact means outwardly of the opposite outer faces of the housing parts for retaining the container parts together.

3. An electrical connector adapted to be attached to a cable, comprising a generally cylindrical shell having an open forward end, means adjacent the rear endof the shell adapted to be attached to an end of the cable, an assembly carrying two contacts supported adjacent the forward end of the shell, means hermetically sealing the contact assembly to the shell, a circuit device located within the shell rearwardly of the sealing means, said circuit device comprising a generally disc-like insulating housing extending transversely of the shell, said circuit device comprising an electrically insulating housing having two parts forming two separated cavities therebetween, a circuit element in each cavity, two electrically conducting means retaining the two parts of the housing in closed position, each retaining means comprising an electrically conducting means penetrating both housing parts at each of the cavities and retaining the housing parts together, each such retaining means being connected to its respective circuit element within the cavity and having a socket therein aligned with the respective contacts, each contact having a rearward extension received in the socket of its respective retaining means, and terminal means on the circuit device adapted to be connected to a conductor of said cable.

4. An electrical connector adapted to be attached to a cable, comprising a shell having an open forward end, means adjacent the rear end of the shell adapted to be attached to an end of the cable, an assembly carrying at least one contact supported adjacent the forward end of the shell, means hermetically sealing the contact assembly to the shell, the sealing means having an annular portion located coaxially of and within the shell rearwardly of the contact assembly, a circuit device located within the shell rearwardly of the sealing means, said circuit device comprising an electrically insulating housing having two parts forming a cavity therebetween, the forward peripheral edge portion of the housing substantially contacting said annular portion of the sealingmeans, a circuit element in the cavity in the housing, electrically conducting means retaining the two parts of the housing in closed position, said retaining means being electrically connected to the contact, and terminal means on the circuit device adapted to be connected to a conductor of said cable.

5. An electrical circuit device as claimed in claim 2, w herein the contact means is a sleeve adapted to receive an electrically conducting pin therewithin, the opposite ends of the sleeve being flared outwardly of the outer surfaces of the housing parts.

6. An electrical apparatus having two closely spaced parallel pins electrically insulated from eachother, an electrical circuit device mounted upon said pins, said device comprising an electrically insulating housing, comprising two aligned and confronting disc-like parts having a cavity therebetween, a circuit element in said cavity, two parallel elongated sleeves extending through both parts of the housing and the cavity, means on the sleeves retaining the two parts of the housing in closed position, a circuit element in said cavity, leads from the element connected within the cavity to the respective sleeves, said pins being telescoped within and electrically connected to the respective sleeves.

7. An electrical apparatus as claimed in claim 6, comprising a plurality of parallel pins including a set comprising a plurality of upper pins and a set comprising a plurality of lower pins, the two sets of pins generally confronting each other but being displaced through a substantial angle from eachother, a plurality of cavities in the housing, an electrical element in each of said cavities, a plurality of sleeves extending through each cavity and connected to leads from the respective elements, one sleeve at each cavity being telescoped over and electrically connected to an upper pin and one sleeve at each cavity being telescoped over and electrically connected to a lower pm.

8. An electrical connector adapted to be attached to a cable having at least one conductor, comprising a shell having an open forward end, means within the shell and adjacent the rear end of the shell adapted to be attached to an end of the cable, an assembly carrying at least one contact supported within the shell adjacent the forward open end of the shell, means connecting the contact assembly to the shell, a circuit element located wholly within the shetll rearwardly of the assembly and the con necting means and connected in circuit with the contact, and terminal means on the element adapted to be connected to a conductor of said cable.

9. An electrical connector as claimed in claim 8, wherein the circuit element is a resistor.

10. In an electrical circuit assembly having an electrical connector and a cable having at least one conductor attached thereto, the improved connector which comprises a shell having an open forward end, means within the shell and adjacent the rear end of the shell attaching the connector to the cable, an assembly within the shell carrying at least one contact located adjacent the forward open end of the shell, means hermetically sealing the contact assembly to the shell, a circuit element located wholly within the shell rearwardly of the assembly and the sealing means and connected in circuit with the contact, and terminal means on the element connected to a conductor of said cable.

11. An electrical connector as claimed in claim 10, wherein the circuit element is a resistor.

12. In an electrical circuit having an electrical connector and a cable having two conductors therein attached thereto, the improved connector which comprises a shell having an open forward end, means adjacent the rear end of the shell attaching the connector to the cable, an assembly within the shell carrying two contacts located adjacent the forward end of the shell, means hermetically sealing the contact assembly to the shell, a pair of circuit elements located within the shell rearwardly of the sealing means, each element being connected in series with its respective contact, and terminal means on the element connected to the respective conductors of the cable.

13. An electrical circuit as claimed in claim 12, wherein the circuit elements are resistors.

14. An electrical connector adapted to be attached to a cable, comprising a shell having an open forward end,

means adjacent the rear end of the shell adapted to be attached to an end of the cable, an assembly carrying at least one contact supported adjacent the forward end of the shell, means hermetically sealing the contact assembly to the shell, a circuit device located within the shell rearwardly of the sealing means, said circuit device comprising an electrically insulating housing having two parts forming a cavity therebetween, a circuit element in said cavity, electrically conducting means retaining the two parts of the housing in closed position, said retaining means being electrically connected to the contact, and terminal means on the circuit device adapted to be connected to a conductor of said cable.

15. An electrical connector as claimed in claim 14, wherein the shell is generally cylindrical, the housing is generally disc-like and extends transversely of the shell, the retaining means has a socket therein aligned with the contact, and the contact has a rearward extension received in said socket.

16. In an electrical thermocouple circuit having a sealed electrical connector and a cable attached thereto, the improved connecter which comprises a shell having an open forward end, means adjacent the rear end of the shell sealingly attaching the connector to the cable, an assembly within the shell carrying two spaced parallel contacts electrically insulated from each other and from the shell, and located adjacent the forward end of the shell, means hermetically sealing the contact assembly to the shell, a disc-like housing extending transversely of and within the shell rearwardly of the sealing means, two compensating resistors in the housing, means connecting a first end of each of the resistors to the respective contacts, and means connecting the other ends of the resistors to the respective ones of two conductors of the cable connected to the shell.

17. A thermocouple circuit as claimed in claim 16, wherein the housing has two first socket members aligned with and confronting the contacts, said socket members being connected to the first ends of the respective resistors, and rearwardl projecting extensions on the contacts received in and making electrical contact with the first socket members, the housing has two second socket members open toward the rear of the shell, pins in said second sockets, and means connecting said pins to the respective ones of two conductors of the cable connected to the shell.

References Cited in the file of this patent UNITED STATES PATENTS 

